钡锶垢除垢影响因素研究

Influence Factors on Barium/Strontium Sulfates Scaling Removal

针对胜利油田临盘采油厂L95站和T9站水样,考察了结垢时间、搅拌速度、结垢温度、Ba^(2+)/Sr^(2+)浓度、SO_4^(2-)浓度等因素对钡锶垢结垢的影响,并进行钡锶混合垢结垢实验。结果表明,在10min内钡锶垢的结垢率已基本稳定,BaSO_4结垢率约98%,SrSO_4结垢率约22%。结垢时间、搅拌速度对钡锶垢结垢率基本无影响。温度(30~80℃)、Ba^(2+)浓度对BaSO_4结垢率的影响较小。随SO_4^(2-)浓度增加,BaSO_4结垢率增大,当SO_4^(2-)浓度由1.53 mmol/L增至3.06mmol/L时,BaSO_4结垢率从94.68%增至99.97%,继续增大SO_4^(2-)浓度,BaSO_4结垢率不变。SrSO_4结垢率随温度升高、Sr^(2+)及SO_4^(2-)浓度增加而显著增大,当SO_4^(2+)与Sr^(2+)浓度为24mmol/L和3 mmol/L、温度大于80℃时,SrSO_4结垢率达80%。当[Ba^(2+)]/[Sr^(2+)]/[SO_4^(2-)]浓度比为2:1:6时,钡锶混合垢的结垢率为93.75%。采用连续定点结垢技术,加入6倍过量的SO_4^(2-),20 min后钡锶垢总结垢率稳定在91%左右。适度补加SO_4^(2-)作为结垢促进剂是提高钡锶垢总结垢率的有效途径。

Experiments of mixing barium/strontium sulfates scale formation, as well as effects of reaction time, temperature, stirring rate, concentration of Ba2＋/Sr^2＋ and SO4^2- on the formation of barium/strontium sulfates scale at L95 and T9 production sites in Linpan oil production factory of Shengli oilfield, were investigated in the paper. The results showed that the scaling rate of barium/strontium scale was basically stable in ten minutes. The scaling rate of BaSO, was above 98%, while that of SrSO4 was about 22%. Reaction time and stirring rate had no effect on the scaling rate of barium/strontium sulfates scale, while the temperature （30--80℃） and the concentration of Ba^2＋ had a little influence on the scaling rate of BaSO,. The scaling rate of BaSO4 increased with increasing SO42- concentration, and that increased from 94.68% to 99.97% when the concentration of SO,2- increased from 1.53 mmol/L to 3.06 mmol/L. The scaling rate of SrSO, had greatly increased with increasing temperature as well as the concentration of SO42- and Sr^2＋. When the concentration of SO42- and Sr^2＋ increased to 24 mmol/L and 3 mmol/L respectively, the scaling rate of SrSO, scale was nearly to 80% at the temperature higher than 80℃. Besides, When the concentration ratio of [Ba^2＋], [Sr^2＋] and [SO42-] was 2：1：6, the total scaling rate of mixed barium/strontium sulfates scale was as high as 93.75%. Because of the addition of 6 times concentration of SO42-, the total scaling rate of barium/strontium sulfates scale was about 91% with 20 min scaling time by using the continuous point scaling technology. In general, it was an effective way to improve the scaling rate of barium/strontium sulfates scale by increasing SO42- as scale accelerator.